AN AMERICAN surfer is reportedly in intensive care after being attacked by a shark in Bali on Monday.

The man, known only as Ryan from San Diego, was surfing at Balian in western Bali when he was bitten on the arm by the shark.

Local resident Twiggy Van Ryan, 47, from Cronulla was having breakfast on the beach around 7:15am when he noticed him coming out of the water holding his elbow.

“I thought he just injured himself and his girlfriend came running up the beach and said it was a shark attack,” Van Ryan told news.com.au.

He jumped into action along with others to get the victim and his German girlfriend to hospital.

“As much as I was trying to help, I didn’t stop to consider how much blood he’d already lost. He blacked out on the beach for a little while, less than a minute,” he said, adding that the victim apparently surfed a wave in after the attack.

“I guess the most unnerving thing was that there have been a few attacks up here in Bali. This one was what I would refer to as a more aggressive manner.

“It wasn’t easy to call it a mistake. Other people had been bitten on the hand or foot in murky water, this one had more of an aggressive undertone to it.”

Mr Van Ryan said it was likely to have been a bull shark as the surfing spot was just outside a river mouth, and it probably came from behind as the victim was sitting on his board waiting for a wave.

Twiggy Van Ryan was back in the water after the attack.Source:Facebook

“If it had got him on the thigh, he would have a lot more to worry about.”

But the scary scene still didn’t deter him from his morning surf - he simply moved 100 metres down the beach and said he was proud to see locals back in the water the following morning.

“I just thought it was important to get into the water otherwise the shark might have got a foot bigger in my mind every hour.

“At the end of the day it was the old ‘lightning strikes’ thing. Up here we’re used to it.”

Mr Van Ryan said he hopes news of the attack doesn’t put tourists off the tiny area that relies on surfers as a source of income, but said most people realise the dangers are statistically low.

“You’re going to put your life in your hands a lot more on the ride up here than you do in the water. For me the situation in the water is not a big deal.”

Van Ryan posted on his Facebook account, saying he had spoken to friends of the victim who claimed Ryan was doing well after undergoing surgery.

“Also I spoke to friends of the bite victim and he is recovering well after surgery, good news they say no ligament damage just heaps of stitches and major bruising, muscle tears etc,” he wrote.